The present invention relates generally to support devices for installing electrical outlet boxes or the like, and, more particularly, to variable length support hangers for mounting ceiling boxes between a pair of ceiling joists. However, it will be understood that although the present invention is described with respect to ceiling boxes suspended from ceiling/floor joists, it will be equally applicable to other outlet boxes which are to be mounted at a point between two adjacent support studs or the like.
In the installation of lighting fixtures in or to ceilings, it has become standard practice to mount the electrical distribution portion of the fixture within a ceiling box to which at least a portion of the fixture is also usually fastened. The ceiling box is generally supported over an opening in the ceiling (usually constructed of the same plasterboard or "sheetrock" as the interior walls) by a hanger bar attached to and suspended from the two ceiling/floor joists adjacent the opening, with the ceiling box assembly mounted to the joists before the ceiling is installed.
In general, the hanger bar is usually made up of a pair of slidably telescoping support members which are adapted to be secured to the joists by nails or the like. When the electrician sets about mounting the ceiling box to the joists, he can estimate or measure the inter-joist spacing and tighten the ceiling box on the bar hanger when the ends of the hanger define a distance equal to the inter-joist spacing so that relative movement between two members are prevented as he attempts to attach the bar hanger to the sides of the joists. However, if his estimate is not precisely correct, or if there are irregularities in the inter-joist spacings at the point of installation, he must loosen the ceiling box to adjust the length of the hanger, or otherwise try to manipulate the hanger members to arrive at the precise joist spacing to complete installation.
Alternatively, he can initially leave the ceiling box loose on the hanger and try to adjust the length of the hanger while attempting to attach each end of the hanger to the joists. However, with such loose assembly, the bar hangers will be relatively awkward to handle and could become completely dis-assembled while the electrician is attempting installation. In either event, mounting the ceiling box to the joists can be a time-consuming, inconvenient and possibly dangerous operation.
Therefore, it is an object of the present invention to provide a new and improved mounting assembly for electrical ceiling boxes and the like. It is another object of the present invention to provide a new and improved support hanger for ceiling boxes and the like, which is capable of generally locking the relative position of the hanger members prior to installation.
It is also an object of the present invention to provide a new and improved support hanger for ceiling boxes and the like, wherein the distance between the joist-mounting portions of the support hanger can be set and locked at desired lengths yet can be adjusted by small amounts to accommodate irregularities in the nominal inter-joist spacing.
It is a further object of the present invention to provide a new and improved hanger for ceiling boxes and the like wherein the distance between the joist-mounting portions of the support hanger can be adjustably locked at more than one predetermined length to accommodate different nominal joist spacings.
It is another object of the present invention to provide a new and improved support hanger for mounting ceiling boxes and the like to ceiling joists, which prevents separation of the support hanger members when a substantially heavy load is applied to the ceiling box or the fixture mounted thereto so that the support hanger will not fail under such loading, particularly if subjected to a relatively high temperature.
It is a further object of the present invention to provide a new and improved support hanger for mounting ceiling boxes and the like to ceiling joists, wherein the bar hanger can be adjustably lockably assembled so that the locking means tends to become further engaged when an attempt is made to pull the hanger apart.
It is yet another object of the present invention to provide a new and improved support hanger for mounting ceiling boxes and the like to ceiling joists, wherein the bar hanger can be adjustably lockably assembled and the ceiling box can remain loosely attached thereto during the entire installation procedure.
Objects and advantages of the invention are set forth in part herein and in part will be apparent herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the structures, instrumentalities and combinations defined in the appended claims. Accordingly, the present invention resides in the novel parts, structures, arrangements, combinations and improvements herein shown and described.